package com.mango.gulimall.product.service.impl;

import com.mango.gulimall.product.service.CategoryBrandRelationService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.mango.common.utils.PageUtils;
import com.mango.common.utils.Query;

import com.mango.gulimall.product.dao.CategoryDao;
import com.mango.gulimall.product.entity.CategoryEntity;
import com.mango.gulimall.product.service.CategoryService;
import org.springframework.transaction.annotation.Transactional;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {


    @Autowired
    CategoryBrandRelationService categoryBrandRelationService;
    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        //1查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);
        //2.组装成父子结构
        //2.1 找到所有的一级分类
        List<CategoryEntity> level1Menus = entities.stream().filter(categoryEntity ->
             categoryEntity.getParentCid() == 0
        ).map((menu)->{
            menu.setChildren(getChildren(menu,entities));
            return menu;
        }).sorted((menu1,menu2)->{
            return (menu1.getSort()==null ?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());
        return level1Menus;
    }

    @Override
    public void removeMenuByIds(List<Long> asList) {
        //TODO  删除之前先判断是否被引用了
        baseMapper.deleteBatchIds(asList);
    }

    @Override
    public Long[] findCatelogPath(Long catelogId) {
        List<Long> paths = new ArrayList<>();
        List<Long> parentPath = findParentPath(catelogId, paths);
        Collections.reverse(parentPath);
        return parentPath.toArray(new Long[parentPath.size()]);
    }

    @Transactional
    @Override
    public void updateCascade(CategoryEntity category) {
        this.updateById(category);
        categoryBrandRelationService.updateCategory(category.getCatId(),category.getName());
    }

    /** 递归找出父id
     * @param catelogId
     * @return
     */
    private  List<Long> findParentPath(Long catelogId,List<Long> paths){
        //收集当前节点id
        paths.add(catelogId);
        CategoryEntity byId = this.getById(catelogId);
        if(byId.getParentCid()!= 0 ){
            findParentPath(byId.getParentCid(),paths);
        }
        return paths;
    }
    /** 获取某一个菜单的子菜单 递归查找
     * @param root  当前菜单
     * @param all   所有菜单
     * @return
     */
    private List<CategoryEntity> getChildren(CategoryEntity root,List<CategoryEntity> all){
        List<CategoryEntity> children = all.stream().filter(categoryEntity -> {
            //如果当前菜单父id等于指定菜单的id，说明当前菜单就是指定菜单的下级菜单
            return categoryEntity.getParentCid().equals(root.getCatId());
        }).map(categoryEntity->{
            //找到子菜单
            categoryEntity.setChildren(getChildren(categoryEntity,all));
            return categoryEntity;
        }).sorted((menu1,menu2)->{
            //菜单的排序
            return (menu1.getSort()==null ?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());
        return children;

    }
}